Malaysia Airline's missing Flight MH370 flew for over an hour after losing contact

March 12, 20144:13pm

How You Can Help in the Search for Flight 3703:56

You can help search for the missing Malaysia Airlines plane, thanks to a website called Tomnod.com. It allows anyone to comb the area where rescue workers are searching using satellite images. The WSJ's Deborah Kan speaks to DigitalGlobe’s Luke Barrington.

IT'S the mystery hour that is leaving investigators probing the disappearance of Flight MH370 stumped.

As the fate of Malaysia Airlines Flight MH370 deepens amid reports it may have changed its course, investigators are increasingly baffled by the possibility it continued flying for an hour after losing contact with air traffic control.

The missing aircraft was carrying 239 passengers on crew when it disappeared on Saturday morning while travelling from Kuala Lumpur to Beijing.

The Boeing 777 made its last contact southeast of Vietnam at about 1.30am local time (4.30am AEST), but a senior Malaysian air force official, who declined to be named, told CNN the aircraft showed up on radar for about 70 minutes longer, having apparently moved away from its intended destination, hundreds of miles off course.

It follows earlier comments attributed to Malaysia's air force chief Gen. Rodzali Daud by Malaysian newspaper Berita Harian, in which he said that radar at a military base had tracked the jet as it radically changed its course.

He was quoted as saying that a final signal at 2.40am showed the plane to be near Palau Perak at the northern approach to the Strait of Malacca, a busy waterway that separates the western coast of Malaysia and the Indonesian island of Sumatra.

However, he has since denied making the comments, saying the newspaper published "what is clearly an inaccurate and incorrect report."

Central Queensland University aviation expert Ron Bishop said the aircraft would use three forms of technology to communicate.

These are VHF radio, a messaging-based system called ACARS and a transponder which sends a unique signal back to the radar station, which can differentiate them from other aircraft.

Mr Bishop said it was "possible" that all three of the communications systems were not working or had been deliberately turned off.

"Any system on the plane could conceivably fail," he said.

News_Image_File: In mourning and clinging to a miracle ... relatives of passengers from the missing Malaysia Airlines Boeing 777-200 plane leave after a meeting with the Malaysian ambassador.

He said the pilots could also have been too busy attempting to deal with an emergency to get in touch with air traffic control, and had headed back to base in line with aviation protocols.

In aviation, the order of dealing in a crisis is to aviate, navigate and lastly communicate.

Mr Bishop said this would support a theory that the aircraft suffered a mechanical and systems failure and was headed back to home base.

"There might be procedures for them to turn back to home if there is a problem and they think they can make it," he said.

"After all, that's where all their maintenance support would be."

Former Qantas head of safety Ron Bartsch said the only logical explanation for the change of course was that the pilot or a member of the aircrew had decided to divert from the flight path without informing air traffic control.

"The only logical explanation for that is that there was a deliberate move by the pilots to pilot the aircraft to where it's going there," he told ABC Radio.

"The main reason for that is that communications with air-traffic control when it was in the Malaysian-Vietnamese airspace, is that it lost radar contact, which means there would have to have been a deliberate act by the pilots to switch off the transponder so the aircraft couldn't be tracked by civilian radar."

He said while this would have made it disappear from civilian radar, it is entirely possible that military radar "may have been able to track it separately."

It comes as it emerges that officials from the US Federal Aviation Administration warned of a potential weakness in Boeing 777s that could lead to rapid decompression or the plane breaking up four months before the disappearance of Malaysia Airlines Flight 370.

News_Module: Plane crash theories

The FAA put out an Airworthiness Directive in November triggered by reports of cracking in the fuselage skin underneath the aircraft's satellite antennae.

The association, which is responsible for supervising the safety of American-made aircraft, directed airlines to check for corrosion under the fuselage skin.

It said this could potentially lead to a Boeing 777 breaking up or a rapid decompression in which passengers and crew could lose consciousness.

The FAA called for additional checks to be incorporated into the routine maintenance schedule of the worldwide 777 Boeing fleet.

The missing Malaysia Airlines aircraft last underwent maintenance on February 23 - 12 days before its last flight.

Malaysia Airlines said no issues were identified with the plane.

Its next check was due on June 19.

News_Image_File: Still no sign ... officials sent by Chinese government to Malaysia at a special meeting with Malaysian officials over the missing Malaysia Airlines Boeing 777-200 plane.

Mr Bartsch discounted the possibility that a sudden loss of cabin pressure had killed the passengers and crew instantly, and that the aircraft might have flown by itself for many hours.

"The fact that this has gone in another direction means that there would have to have been some actual positive action by a crew member … to actually have it end up in Malacca, if that was in fact the case."

Aside from radio, ACARS and a transponder, aircraft can be picked up by airport radar stations from a distance of about 100km, while air route surveillance radar can track planes up 400km away.

A radar antenna sends electromagnetic waves that reflect from the surface of an aircraft and almost instantly return, allowing controllers to calculate how far away a plane is.

The antenna is mounted on a rotating platform, sending and receiving signals 360 degrees across the sky, enabling the plane's direction to be tracked by constant sweeps.

However, experts say that there are areas of the world - including parts of jungle Malaysia - where a plane can effectively fly off the radar.

Low-flying planes can sometimes avoid radar detection. There is no set height they must be under, but the farther away they are from a radar station, the higher they can be because of the angle of the radar antenna and the curvature of the Earth.